Magnetism and rotation effect on surface waves in fibre-reinforced anisotropic general viscoelastic media of higher order

S. M. Abo-Dahab,A. M. Abd-Alla,Aftab Khan 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.8

The aim of this paper is to study the propagation of surface waves in a rotating fibre-reinforced viscoelastic media of higher order underthe influence of magnetic field. The general surface wave speeds derived to study the effects of rotation and magnetic field on surfacewaves. Particular cases for Stoneley, Love and Rayleigh waves are also discussed and dispersion relation for the waves has been deduced. The results obtained in this investigation are more general in the sense that some earlier published results are obtained from our result asspecial cases. For order zero our results are well agreement to fibre-reinforced materials. Also by neglecting the reinforced elastic parameters,the results reduce to well known isotropic medium. It is observed that in a rotating medium the surface waves are dispersive. Also magnetic effects play a significant roll. It is observed that Love wave remain unaffected in a rotating medium but remain under theinfluence of magnetic field. Rayleigh waves are affected by rotation and magnetic field whereas Stoneley waves are independent ofMaxwell stresses. It is also observed that, surface waves cannot propagate in a fast rotating medium or in the presence of magnetic fieldof high intensity. Numerical results for particular materials are given and illustrated graphically. The results indicate that the effect ofrotation and magnetic field are very pronounced.

Effects of voids and rotation on plane waves in generalized thermoelasticity

S. M. Abo-Dahab,A. M. Abd-Alla,S. R. Mahmoud 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.12

In the present paper, we study the influence of rotation, thermal and voids parameters on the reflection phenomenon of plane waves in generalized thermoelastic solid with one relaxation time. The governing field equations for isotropic and homogeneous thermoelastic half-space with voids and rotation are formulated in the context of Lord and Shulman theory of generalized thermoelasticity. The solutions of these governing equations indicate the existence of four coupled plane waves, namely; 1 P ;P 3 ;P and 4 P waves in the thermoelastic medium. The boundary conditions at stress-free thermally insulated surface are satisfied to obtain the system of four nonhomogenous equations in the reflection coefficients of various reflected waves for the incidence of 1 P wave. A particular material is modeled as the thermoelastic solid half-space to compute the complex absolute values of speeds and reflection coefficients. The speeds and reflection coefficients are shown graphically to observe the influences of rotation, thermal relaxation time and voids parameters.

Propagation of p- and T-waves in solid-liquid of thermoelastic media subjected to initial stress and magnetic field in the context of CT-theory

S. M. Abo-Dahab,A. M. Abd-Alla,A. Kilicman 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.2

The effect of magnetic field and initial stress on plane wave propagation is discussed. We have investigated the problem of reflectionand refraction of the thermoelastic wave at a magnetized solid-liquid interface in presence of initial stress. In the context of the CT-theory(Classical dynamical theory) of thermoelasticity, the problem has been solved. The boundary conditions at the interface for (i) displacementcontinuity, (ii) vanishing the tangential displacement, (iii) continuity of normal force per unit initial area, (iv) tangential force perunit initial area must vanish, and (v) continuity of temperature are applied. The amplitude ratios for the incident p- and T-waves havebeen obtained. The reflection and transmitted coefficients for the incident waves are computed numerically, considering the initial stressand magnetic field effect and presented graphically. Comparisons are made with the results in the absence and presence of initial stressand magnetic field. The results indicate that the effect of initial stress and magnetic field on wave propagation are very pronounced.

Effect of gravity field, initial stress and rotation on the S-waves propagation in a non-homogeneous anisotropic medium with magnetic field

S. M. Abo-Dahab,A. M. Abd-Alla,Ibrahim H. El-Sirafy 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.8

In this paper, we investigated the propagation of shear wave under the influences of the magnetic field, gravitational field, rotation andinitially stressed in anisotropic non-homogeneous incompressible elastic medium. It is well known in the literature that the earth mediumis not at all initial stress free and homogeneous throughout, but it is initially stressed and non-homogeneous. The frequency equation thatdetermines the velocity of the shear waves has been obtained. Keeping these things in mind, we have discussed the frequency equation inan initially stressed, non-homogeneous medium with gravity field, magnetic field, and rotation. It has been observed that the inhomogeneityparameter, gravity field, magnetic field, and the initial stress play an important role in the propagation of S-waves propagation. Thenumerical values on the dimensionless phase velocities are calculated and presented graphically to illustrate the dependences upon gravityfield, initial stress, magnetic field, anisotropy and rotation comparatively. The results indicate that the effects of gravity field, initialstress, magnetic field, anisotropy, and rotation are very pronounced.

Reflection of electro-magneto-thermoelastic plane waves in a rotating medium in context of three theories with two-temperature

S.M. Abo-Dahab,Mohamed I.A. Othman,Ohoud N.S. Alsebaey 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.78 No.1

In this paper, we established the generalized thermoelasticity phenomenon in an isotropic elastic medium considering the electromagnetic field, rotation and two-temperature. Three theories of generalized thermoelasticity have been applied: Lord-Shulman (one relaxation time), Green-Lindsay (two relaxation times), as well as the coupled theory. We discussed some particular cases in the context of the wave propagation phenomenon in thermoelasticity. From solving the fundamental equations, we arrived that there are three waves: P-, T- and SV-waves that we calculated their velocities. The boundary conditions for mechanical stress and Maxwell’s stress and thermal insulated or isothermal have been applied to determine the amplitudes ratios (reflection coefficients) for P-, T - and SV waves. Some utilitarian aspects are obtained from the reflection coefficients, presented graphically, and the new conclusions have been presented. Comparisons are made for the results predicted by different theories (CT, LS, GL) in the absence and presence of the electro-magnetic field, rotation, as well as twotemperature on the reflection of generalized thermoelastic waves. The results obtained concluded that the external parameters as the angle of incidence, electromagnetic field, rotation as well as the theories parameters have strong effect on the phenomenon.

Rotational effect on Rayleigh, Love and Stoneley waves in non-homogeneous fibre-reinforced anisotropic general viscoelastic media of higher order

S.M. Abo-Dahab,A.M. Abd-Alla,Aftab Khan 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.58 No.1

In this paper, we investigated the propagation of surface waves in a nonhomogeneous rotating fibre-reinforced viscoelastic anisotropic media of higher order of nth order including time rate of strain. The general surface wave speed is derived to study the effect of rotation on surface waves. Particular cases for Stoneley, Love and Rayleigh waves are discussed. The results obtained in this investigation are more general in the sense that some earlier published results are obtained from our result as special cases. Also results for homogeneous media can be deduced from this investigation. For order zero our results are well agreed to fibre-reinforced materials. Also by neglecting the reinforced elastic parameters, the results reduce to well known isotropic medium. It is also observed that, surface waves cannot propagate in a fast rotating medium. Comparison was made with the results obtained in the presence and absence of rotation and parameters for fibre-reinforced of the material medium Numerical results are given and illustrated graphically. The results indicate that the effect of rotation and parameters for fibre-reinforced of the material are very pronounced.

Influence of variable thermal conductivity on waves propagating through thermo-elastic medium

Sayed M. Abo-Dahab,Adnan Jahangir,Adiya Dar 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.4

We investigated the influence of variable thermal conductivity on waves propagating through the elastic medium. Infinitesimal deformation results in generation of thermal signal, and is analyzed by using dual phase lag heat (DPL) conduction model. The medium considered is homogenous, isotropic and bounded by thermal shock. The elastic waves propagating through the medium are considered to be harmonic in nature, and expressions for the physical variables are obtained accordingly. Analytically, we obtained the expressions for displacement components, temperature, micro-temperature component and stresses. The theoretical results obtained are computed graphically for the particular medium by using MATLAB.

Long wavelength peristaltic flow in a tubes with an endoscope subjected to magnetic field

Abd-Alla, A.M.,Abo-Dahab, S.M.,El-Semiry, R.D. 한국유변학회 2013 Korea-Australia rheology journal Vol.25 No.2

In this paper, this study examines problem of peristaltic flow in a tubes with an endoscope subjected to magnetic field. Effect of an endoscope and magnetic field on the peristaltic flow of a Jeffrey fluid through the cylindrical cavity between concentric tubes has been investigated. The analytical expressions for the pressure gradient, velocity, pressure rise, friction force on the inner and outer tubes and shear stress are obtained in the physical domain. Effect of the non-dimensional wave amplitude, the magnetic field, the ratio of relaxation to retardation time, the radius ratio and the non-dimensional volume flow are analyzed theoretically and computed numerically. Comparison were made with the results obtained in the presence and absence of magnetic field and an endoscope. The results indicate that the effect of the non-dimensional wave amplitude, magnetic field, ratio of relaxation to retardation time, radius ratio and non-dimensional volume flow on peristaltic flow are very pronounced.

Soret effect and chemical reaction on a nonlinear, heated, convective flow of a MHD mixed nanofluid within a porous medium due to an extending surface

Abdelhafez M. A.,Abo-Dahab S. M. 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.80 No.6

This paper aims to investigate the impact of the sort chemical response on the nonlinear heated flow of an MHD mixed convection nanofluid because of chemical reactions with an extended surface and the porosity of that surface. The transfer of heat within a nanofluid exposed to a magnetic scope and convective boundary settings for getting the physical meaning of the phenomenon of convection (velocity, temperature, concentration, Nusselt number, and Sherwood number) are explored. The governing partial differential equations of the boundary category are found to reduce to ordinary differential equations, with the transition method of similarity is considered. The converted equations in numbers regarding the method of an effective numerical shooting that applies to the 4th–5th order of the Runge–Kutta technical scheme is resolved. The outcomes for the dimensionless velocity, concentration profiles, temperature, and Nusselt number decrease, where Sherwood number can be displayed using figures to show the phenomena's physical meaning. The findings of the were compared with that in study the literature and were found to agree with the literature results when the novel external parameters, such as chemical reaction, porosity, and MHD parameters vanish.

Wave propagation in fibre-reinforced anisotropic thermoelastic medium subjected to gravity field

Abd-Alla, A.M.,Abo-Dahab, S.M.,Bayones, F.S. Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.2

The objective of this paper is to investigate the surface waves in fibre-reinforced anisotropic thermoelastic medium subjected to gravity field. The theory of generalized surface waves has firstly developed and then it has been employed to investigate particular cases of waves, viz., Stoneley waves, Rayleigh waves and Love waves. The analytical expressions for displacement components, force stress and temperature distribution are obtained in the physical domain by using the harmonic vibrations. The wave velocity equations have been obtained in different cases. The numerical results are given and presented graphically in Green-Lindsay and Lord-Shulman theory of thermoelasticity. Comparison was made with the results obtained in the presence and absence of gravity, anisotropy, relaxation times and parameters for fibrereinforced of the material medium. The results indicate that the effect of gravity, anisotropy, relaxation times and parameters for fibre-reinforced of the material medium are very pronounced.